Association of bacteria with bryozoan larvae

Seven species of marine bryozoans were examined for the presence of bacteria associated with the larvae. In three species (Bugula neritina, B. pacifica, and B. simplex), rod-shaped bacteria were consistently observed in the pallial sinus of the larvae, independent of geographic location, year, or season. Larvae of closely related bryozoans (B. stolonifera, B. turrita, Scrupocellaria bertholetti, and Tricellaria occidentalis) occurring sympatrically with those containing bacteria lacked this apparent symbiosis. Those bryozoans examined that possessed the bacteria-larva association are among the most frequently encountered fouling bryozoans.